How do you denote the dihedral group of order n?
This is not a question of “vim or emacs” or “tabs or spaces” sort, but still there are two notations in use. Some sources use Dn to denote a dihedral group of order n, and some others – a dihedral group of order 2n. Both notations are also reflected in mathematical software.
For example, in GAP
DihedralGroup(n) returns a group of order n:
and in SageMath – a group of order 2n:
Let us look at other systems: (more…)